In computer systems, partitions are physical or logical mechanisms for isolating operational environments within single or multiple servers. Examples of partitions include “node partitions,” “virtual partitions,” and “resource partitions” that are implemented using various products available from Hewlett-Packard Company. Node partitions (“nPars”) are hard partitions that provide electrical and software isolation. The partitions are implemented using various “cells” that have one or several processors. Various functionality is provided to limit the communication between the cells. Accordingly, any fault within a given nPar cannot impact any other nPar. Virtual partitions (vPars) provide application and operating system isolation. Specifically, each vPar runs its own image of the operating system and can fully host its own applications. Resource partitions may be run within nPars or vPars. Resource partitions are used to dynamically create partitions for applications that benefit from guaranteed dedicated resources, such as CPU resources, networking resources, and/or disk input/output resources. Resource partitions can be implemented using scheduling algorithms (such as fair share schedulers) that control access to the resources of interest.
In addition to providing isolation, partitions provide the ability to shift resources of a computer system from workloads that possess excess resources to workloads that would benefit from additional resources. For example, it is possible to transfer a processor from a given nPar to another nPar, a processor from a vPar to another vPar, or a processor from a resource partition to another resource partition. The interfaces and mechanisms (for nPars) used to perform such transfers depends upon the particular partitions involved.